This invention relates generally to ship repair apparatus and more particularly to apparatus used in conjunction with a ship drain to facilitate the repair of a ship's hull.
Ship decks are usually provided with numerous drains, commonly referred to as "scupper holes", which terminate at drain openings in the ship's hull, located above the water line. The drains extend generally downwardly from the deck and then generally horizontally toward the vertical outer surface of the hull where they terminate. The drains permit rain and sea water collecting on the deck to drain from the deck's surface. The drains also permit the deck to be easily cleaned with a high pressure water hose by draining the wash water from the deck's surface.
However, such drains or scupper holes create problems when the ship is in drydock to have its hull repaired or refurbished. Rain water or wash water which collects on the deck drains through the scupper holes and then flows down the outer surface of the ship's hull, making it difficult if not impossible for work to be done on the hull. For example, the draining water, together with the grit and grime it carries, can ruin the finish of a freshly painted hull or make it difficult to sand the hull.
Unsuccessful attempts have been made to solve this problem. For example, plugs have been inserted into the drain openings to plug the drains. Such plugs have proved unsatisfactory because water accumulates in the drain and eventually backs up onto the deck, creating an unsafe condition and making it difficult to do any work on the deck. Also, such plugs inherently leak, even when wrapped with rags, and hence still do not solve the drainage problem. Some success has been had with a modified plug having an axially extending bore and a pipe inserted into such bore to permit water in the drain to be conveyed away from the hull's outer surface. Although the modifed plug alleviates the water accumulation problem, it still permits water to leak from the drain and interfere with the work being done to the hull.
Another attempt at solving the aforementioned problem involves tack welding a metal trough-like member to the hull just beneath each drain opening. This method is time consuming and costly in that it requires one or more welders to tack weld many (more than fifty in some cases) troughs to the sides of the ship. Even without full welds, the work required to install and remove the numerous troughs is considerable. Further, the troughs still do not solve the leakage problem because they provide an ineffective seal at the drain opening, permitting water at the welded joint to leak down the hull's outer surface.
Accordingly, there remains a need for a ship deck drain apparatus which can be quickly and easily installed and removed with a minimal amount of labor, eliminates the leakage of water from the drain down the side of the ship, and keeps water from accumulating in the drain.